Molds for rubber soled footwear



&830324 F. FARMER ET AL MOLDS FOR RUBBER SOLED FOOTWEAR Aprl 15, 1958 2Sheets-Sheet 1 Filed May 15, 1952 IN V N TORS Apri! 5, 1958 F. FARMERETAL 2,830,324

MOLDS FOR RUBBER SOLED FOOTWEAR 2 Sheets-Sheet 2 Filed May 13. 1952United' States Patent O z,s30,324 MOLDS FORRUBBER SOLED FOOTWEAR FredFarner and Andrew Szerenyi, Waynesville, N. C.,

`assignors to Ro-Search, Inc., Waynesvlle, N. C., a corporation of NorthCarolina .Application May13, 1952, Serial No. %7,536

- 4 Claims.' (Cl.18-34) The invention refers to molds as used for themanufacture of shoes with' soles 'containing rubber. Such molds commonlycomprise a last to carry the upper, a frame to shape the outside rim ofthe sole, and a sole plate to shape the bottom surface of the sole. Ifthe sole is made of dense and stifi rubber, the mold is closed and therubber molded in a hydraulic press or by other power means. If the soleis made of porous rubber, it is customary to close and lock the mold byhand using a looking device which is part of the mold.

One object of the invention is to improve molds so that it becomespossible to manufacture footwear with a side rim of dense rubber withoutthe use of costly hydraulic presses. I

Another object of the invention is to improve the mold to permit themolding of rubber to uppers of heavy leather or other less flexiblematerial, which 'hitherto could not be removed from the heated metallasts of the common molds.

Other objects and characteristics of the nvention are clarified inconnection with the drawings, which show in Fig. 1 a schematic side viewof a mold according to the invention, while Figs. 2 and 3 show in largerscale the last, forming part of the mold of Fig. 1, in the closed andopen position respectively.

The mold shown in Fig. 1 consists of a base plate 1 carrying a bottomplate 2 with a protrusion 18 shaped to form the bottom surface and theinside surface of the side rim of the sole. The outside surface and theupper surface of the welt or side rim is shaped by the frame 4 with thelip 19, usually split lengthwise to facilitate demolding of the sole. Aframe holder 5 holds the parts of the frame 4 together and is supportedby springs 17. The last 6 can be placed upon the frame 4. A locking arm11 is fastened with the hingle 15 to the base plate 1, which alsocarries through a hinge 14 a lockng loop 12, held in the lockingposition by a knob 13 of the arm 11. That arm carries a pressure screw9, which can 'be actuated by the handwheel 10 so as to transmit pressurethrough the plate 8 and the adjusting screws 16 to the top 7 of the last6. The last 6 is divided in such manner that a relatively small part ofthe heel and the so-called quarter can be moved, as shown in Fig. 3, bya toggle lever arrangement 24, fastened to the projections 22 and 23 ofthe heel part and the main part of the last respectively The surfaceseparating the heel part 21 from the main part of the heel has thegeometric shape of a cylnder with the center line 26 located at theinstep of the last. This is essential not only because it permitseffective foreshortening of the last while in the upper, but alsobecause it permits good fit along the divding surface and with it goodheat transfer from the heated main part of the heel to the part 21.

To use the old described above, material to form a solid rubber side rimor welt, such as a vulcanizable rubber mix, is placed into the cornerformed by the bottom plate 2 and the frame 4. The upper is placed on theforeshortened last 6, the toggle 25 closed and thereby the upper A e,2,830324 pa ente& Apr. 15, 1958 brought into the desired shape, so thatit can be located' against the lip 19 of the frame 4. The arm ll'then is'moved into the position' shown in Fig. 1 and the locking arm ,12 willhold it there. By turning the handwheel 10 `the last 6 withthe upper ismoved downwards, first against the frame 4 until atight seal is obtainedbetween the lip 19 and the upper. As the movement of the last continuesagainst the resistance of the springs 17, the upper together V with ,theframe 4 moves against the rib 18 and molds the rubber mix against theupper, As pressure is exerted only in the area of the side rim or welt,the hand opera- 'Any surplus of rubber may escape in the direction ofthe movement of the last through a gap 27, between frame `4 and bottomplate 2 of between the rib 18 and the shoe bottom.

The insert 20 located in the bottom plate 2 might be removed if only aside rim or a welt of solid rubber is desired and the sole or mid-soleis to be applied in a later operation. Very often it is of advantage toleave the insert 20 in the position shown, and to fill the space betweenthe insert and the shoe bottom with a mix for a porous sole. Such mixwill mold and vulcanize without any outside pressure. The shoe, removedfrom the mold after the vulcanization will be ready for the applicationof a tread-sole. While the rib 18 is shown as an integral part of thebottom plate 2, it might be of advantage for certain types of shoes tomake the rib 18 a separate piece to limit the inside surface of the weltor side rim. Such separate piece might be still a permanent part of themold or might be a pressure resistant, stiff strip of material whichbecomes part of the sole.

The mold according to the invention is not only for the molding ofnatural rubber but also for any other natural or synthetic elastomer orrubber like qualities. The last as described above will be useful notonly for the molding of side-rims or welts only but also for the moldingof full soles as it permits the combination of high strength and uniformheating with the advantages of a fore-shortenable last. As can be seenin Fig. 3 and Fig. 3 the main part of the last can easily accommodateenough electric heating elements 28 to secure adequate and uniformheating. As further improvement the bottom surface of the last is formedby removable pieces 29 and 30, located in the last by pins 31 and heldby set-screws 32 pressing against the preferably tapered pins. The solesurface of the last is correspondingly un-interrupted and smooth so asto avoid unsightly markings on the insole during the moldng. If thepattern of the up-per changes, it is sufiicient to replace the parts 29and 30, without replacing and re-adjusting the whole last.

What We claim is:

1. A mold for the molding and vulcanization of rubber in situ to a shoeupper, comprising a last to carry said upper, a frame to form the topand side surface of a welt, and a bottom plate, means to separate theinside of said welt from the center of the sole, said means comprising aprojection uniformly spaced inside of the molding frame around theperiphery of said sole, and means to exert pressure upon the rubber massconfined between said frame and said projection.

2. A mold for the molding and vulcanization of rubber in situ to a shoeupper, comprsing a last to carry said upper, a frame to form the top andside surface of a welt, and a bottom plate, means to separate the insideof said welt from the center of the sole, said means comprising aprojection uniformly spaced inside of the molding frame around theperiphery of said sole, and means to exert pressure upon the rubber massconfined between said frame 'and said projection, said last dividedintoa main par-t nd :a heel part alnga `cylindrical surface extending' 4*upper, a frame to lforrnuthe top and sidesurface of a we1t, and abottom tplate, means to separate thein si de of said Welt from thecenter of the sole, said means 'comprising a projecton unifo 'mly spacedinside of the molding frame around the periphery of said sole, and meansto exert pressure upon the` rubber mass confined between -s'aid frarheand 'said `projection,- said last. divided into a rai `p`rt`fiid he'elp`r't,fs'ad `p`art`s connected to each tfir' By jtggl lilerswhichgfofe-shorten said `last when pf d nfth'eir closed position holdsaid parts to pret a citn sble s liffa.

in `s`it'u to a 'sho'e u'pp 'r, co'pris'ing a last to carrysaid uppr, a"fime to form the top and side surface of a We`1t,`and'a` bottomplate,'niean`s t'o separate the inside of said welt from the center ofthe sole, said means compris- 'ing si projecton uiformly s'pced insideof the moldng frame around the periphery of said sole, and means toexert pressure ujdn the rubber mass confined between said frame and saidprojection, said last divided into a i main part and heel part movablein relaton thereto and carrying a replaceable sole plate offering asmooth surface towards the nsole and held by pins enterng the main bodyof said last'.

Rferen'csited in the file of this patent UNiTEDsTA TEs PATENTS 399227Healey Mar. 5, 1889 411,6 22 Smith Sept. 24, 1889 574',239 `Butte` fieldDec. 29, 1896 1,660,881 Nie1sen Feb. 28, 1928 1,855,098 Collins Apr. 19,1932 2,178,086 Szerenyi Oct. 31, 1939 2,651,11s Root Sept. s, 1953*FOREIGN `PATENTS '617,22'9

